LightSquared faces challenge from the House

Two US Representatives have tabled an amendment which will stop box 'o frogs wireless plan LightSquared from ever building its network, at least until it can prove a negative.

The amendment requires LightSquared to prove that its planned pan-USA LTE network won't interfere with GPS systems, before the FCC can spend any money altering the company's licence to enable it to build that network. That's despite LightSquared already agreeing to shift frequencies, and ahead of the cross-industry report on the subject which isn't due to be published until next week.

The amendment has been tabled by two Republicans, Steve Austria (Ohio) and Kevin Yoder (Kansas), and leans a little towards hyperbole in claiming that LightSquared is planning "a ground-based mobile broadband system with a signal that is roughly 1 billion times more powerful than satellite-based GPS signals, within a spectrum immediately adjacent to the GPS".

That's also inaccurate, given last week's announcement that LightSquared would be shuffling away from the GPS bands in what must be considered an admission that its service (as originally envisioned) would have caused significant problems for GPS users.

The problem with running right beside the GPS signal is twofold. Firstly, the bell-shaped LightSquared signal will inevitably leak into the neighbouring band, but equally a cheapo (or highly sensitive) GPS receiver will pick up signals from neighbouring bands as it strains to pick up the weak satellite transmission.

LightSquared reckons that its signal is very square (rather than bell-shaped) and so doesn't leak much, and that fewer than half a percent of GPS kit is that cheap/sensitive and that this can be fixed, but it also argues that the GPS industry has had every opportunity to raise this issue years ago and it is more than a little annoyed to have it all come to a head now.

The company points to its FCC filings going back to 2001 which recognise the potential for GPS interference, and takes some responsibility for mitigating it. But LightSquared also wants to share that responsibility, claiming that while it has worked to ensure transmissions don't leak into neighbouring bands, it is up to the GPS industry to ensure receivers are only receiving in the GPS band, as the FCC put it:

"We emphasize that responsibility for protecting services rests not only on new entrants but also on incumbent users themselves, who must use receivers that reasonably discriminate against reception of signals outside their allocated spectrum."

The GPS industry has nothing to gain from LightSquared, and no wish to use more expensive receivers which could be tuned more accurately. The incumbent mobile operators have an enormous amount to lose from gaining a competitor who is using (satellite) spectrum for an LTE network.

LightSquared still hasn't the money to build that network, and there aren't any devices that could use it anyway, but if the House of Representatives does pass the amendment then it will be one more hurdle that LightSquared will have to jump if it is ever going to be more than a mad scheme to change the wireless world. ®